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1 | /* |
2 | * Copyright (C) 2016 Maxime Ripard | |
3 | * Maxime Ripard <maxime.ripard@free-electrons.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License as | |
7 | * published by the Free Software Foundation; either version 2 of | |
8 | * the License, or (at your option) any later version. | |
9 | */ | |
10 | ||
11 | #include <linux/clk-provider.h> | |
12 | #include <linux/rational.h> | |
13 | ||
14 | #include "ccu_gate.h" | |
15 | #include "ccu_nkmp.h" | |
16 | ||
17 | struct _ccu_nkmp { | |
18 | unsigned long n, max_n; | |
19 | unsigned long k, max_k; | |
20 | unsigned long m, max_m; | |
21 | unsigned long p, max_p; | |
22 | }; | |
23 | ||
24 | static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate, | |
25 | struct _ccu_nkmp *nkmp) | |
26 | { | |
27 | unsigned long best_rate = 0; | |
28 | unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0; | |
29 | unsigned long _n, _k, _m, _p; | |
30 | ||
31 | for (_k = 1; _k <= nkmp->max_k; _k++) { | |
87ba9e59 | 32 | for (_p = 1; _p <= nkmp->max_p; _p <<= 1) { |
4f728b5d MR |
33 | unsigned long tmp_rate; |
34 | ||
87ba9e59 | 35 | rational_best_approximation(rate / _k, parent / _p, |
4f728b5d MR |
36 | nkmp->max_n, nkmp->max_m, |
37 | &_n, &_m); | |
38 | ||
87ba9e59 | 39 | tmp_rate = parent * _n * _k / (_m * _p); |
4f728b5d MR |
40 | |
41 | if (tmp_rate > rate) | |
42 | continue; | |
43 | ||
44 | if ((rate - tmp_rate) < (rate - best_rate)) { | |
45 | best_rate = tmp_rate; | |
46 | best_n = _n; | |
47 | best_k = _k; | |
48 | best_m = _m; | |
49 | best_p = _p; | |
50 | } | |
51 | } | |
52 | } | |
53 | ||
54 | nkmp->n = best_n; | |
55 | nkmp->k = best_k; | |
56 | nkmp->m = best_m; | |
57 | nkmp->p = best_p; | |
58 | } | |
59 | ||
60 | static void ccu_nkmp_disable(struct clk_hw *hw) | |
61 | { | |
62 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
63 | ||
64 | return ccu_gate_helper_disable(&nkmp->common, nkmp->enable); | |
65 | } | |
66 | ||
67 | static int ccu_nkmp_enable(struct clk_hw *hw) | |
68 | { | |
69 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
70 | ||
71 | return ccu_gate_helper_enable(&nkmp->common, nkmp->enable); | |
72 | } | |
73 | ||
74 | static int ccu_nkmp_is_enabled(struct clk_hw *hw) | |
75 | { | |
76 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
77 | ||
78 | return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable); | |
79 | } | |
80 | ||
81 | static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw, | |
82 | unsigned long parent_rate) | |
83 | { | |
84 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
85 | unsigned long n, m, k, p; | |
86 | u32 reg; | |
87 | ||
88 | reg = readl(nkmp->common.base + nkmp->common.reg); | |
89 | ||
90 | n = reg >> nkmp->n.shift; | |
91 | n &= (1 << nkmp->n.width) - 1; | |
92 | ||
93 | k = reg >> nkmp->k.shift; | |
94 | k &= (1 << nkmp->k.width) - 1; | |
95 | ||
96 | m = reg >> nkmp->m.shift; | |
97 | m &= (1 << nkmp->m.width) - 1; | |
98 | ||
99 | p = reg >> nkmp->p.shift; | |
100 | p &= (1 << nkmp->p.width) - 1; | |
101 | ||
102 | return (parent_rate * (n + 1) * (k + 1) >> p) / (m + 1); | |
103 | } | |
104 | ||
105 | static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate, | |
106 | unsigned long *parent_rate) | |
107 | { | |
108 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
109 | struct _ccu_nkmp _nkmp; | |
110 | ||
111 | _nkmp.max_n = 1 << nkmp->n.width; | |
112 | _nkmp.max_k = 1 << nkmp->k.width; | |
87ba9e59 MR |
113 | _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; |
114 | _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); | |
4f728b5d | 115 | |
87ba9e59 | 116 | ccu_nkmp_find_best(*parent_rate, rate, &_nkmp); |
4f728b5d | 117 | |
87ba9e59 | 118 | return *parent_rate * _nkmp.n * _nkmp.k / (_nkmp.m * _nkmp.p); |
4f728b5d MR |
119 | } |
120 | ||
121 | static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate, | |
122 | unsigned long parent_rate) | |
123 | { | |
124 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
125 | struct _ccu_nkmp _nkmp; | |
126 | unsigned long flags; | |
127 | u32 reg; | |
128 | ||
129 | _nkmp.max_n = 1 << nkmp->n.width; | |
130 | _nkmp.max_k = 1 << nkmp->k.width; | |
87ba9e59 MR |
131 | _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; |
132 | _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); | |
4f728b5d MR |
133 | |
134 | ccu_nkmp_find_best(parent_rate, rate, &_nkmp); | |
135 | ||
136 | spin_lock_irqsave(nkmp->common.lock, flags); | |
137 | ||
138 | reg = readl(nkmp->common.base + nkmp->common.reg); | |
139 | reg &= ~GENMASK(nkmp->n.width + nkmp->n.shift - 1, nkmp->n.shift); | |
140 | reg &= ~GENMASK(nkmp->k.width + nkmp->k.shift - 1, nkmp->k.shift); | |
141 | reg &= ~GENMASK(nkmp->m.width + nkmp->m.shift - 1, nkmp->m.shift); | |
142 | reg &= ~GENMASK(nkmp->p.width + nkmp->p.shift - 1, nkmp->p.shift); | |
143 | ||
144 | reg |= (_nkmp.n - 1) << nkmp->n.shift; | |
145 | reg |= (_nkmp.k - 1) << nkmp->k.shift; | |
146 | reg |= (_nkmp.m - 1) << nkmp->m.shift; | |
87ba9e59 | 147 | reg |= ilog2(_nkmp.p) << nkmp->p.shift; |
4f728b5d MR |
148 | |
149 | writel(reg, nkmp->common.base + nkmp->common.reg); | |
150 | ||
151 | spin_unlock_irqrestore(nkmp->common.lock, flags); | |
152 | ||
153 | ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock); | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | const struct clk_ops ccu_nkmp_ops = { | |
159 | .disable = ccu_nkmp_disable, | |
160 | .enable = ccu_nkmp_enable, | |
161 | .is_enabled = ccu_nkmp_is_enabled, | |
162 | ||
163 | .recalc_rate = ccu_nkmp_recalc_rate, | |
164 | .round_rate = ccu_nkmp_round_rate, | |
165 | .set_rate = ccu_nkmp_set_rate, | |
166 | }; |